Shaping keratin fibres using 2-hydroxypropane-1,2,3-tricarboxylic acid and/or 1,2,3,4-butanetetracarboxylic acid

ABSTRACT

A method for shaping keratin fibres comprising: providing a crosslinking composition, wherein the crosslinking composition comprises: an active agent, wherein the active agent is selected from the group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylic acid, a derivative thereof, and mixtures thereof; and wherein the active agent has a molecular weight of 500 g/mol or less; a photocatalyst; a cosmetically acceptable carrier; and applying the crosslinking composition to keratin fibres, mechanically shaping the keratin fibres with an appliance at a temperature of from about 80° C. to about 180° C. and exposing the composition to electromagnetic radiation having a wavelength of from about 300 nm to about 750 nm. Also a related composition, use, kit and process.

FIELD OF THE INVENTION

A method for shaping keratin fibres comprising: providing a crosslinkingcomposition, wherein the crosslinking composition comprises: an activeagent; a photocatalyst; a cosmetically acceptable carrier; and applyingthe crosslinking composition to keratin fibres, mechanically shaping thekeratin fibres with an appliance at a temperature of from about 80° C.to about 180° C. and exposing the composition to electromagneticradiation having a wavelength of from about 300 nm to about 750 nm.

BACKGROUND OF THE INVENTION

Consumers are constantly demanding products that meet their dailystyling and conditioning needs without damaging the hair. The perceivedand sometimes real impact of various treatments and the implements suchas blow drying and flat iron can have detrimental effects on the acuteand chronic nature of hair.

Permanent methods—or relaxers—usually comprise the steps of applyingonto hair a composition comprising a high pH solution (or combination ofcomponents to generate high pH), leaving on for a protracted time andthen applying a neutralizing composition. A relaxer is a treatmentpredominately used by people of African-descent to permanentlystraighten hair. The treatment relies on either the one-step sodiumhydroxide (lye) or a two step (e.g. guanidine carbonate and calciumhydroxide) to achieve very high pH (pH 12-14).

Semi-permanent benefits can be achieved using redox chemistry such asthioglycolic acid (TGA) and hydrogen peroxide. Here, the curly hair istransformed into the straight hair because the disulfide bonds arebroken by the reaction with TGA. The straighter style is locked induring the oxidation step with hydrogen peroxide.

Non-permanent methods usually comprise the step of heating the hair witha flat-iron or heating element. Methods using such devices incombination with chemically-modifying the internal hair fibres canobtain long-lasting effects e.g. over several months. The BrazilianKeratin Treatments (BKTs) enable the achievement of a straight hairstylethat lasts several months via a shampoo treatment. The key active inBKTs is formaldehyde. The most efficacious treatments (used mainly insalons) rely on high temperature—usually 232° C. (450° F.)—withformaldehyde. Hair treated with products with high concentration offormaldehyde such as Brazilian Blowout delivers semi-permanent straighthair. Over time and following shampooing, the hair reverts back to acurly configuration.

The known methods for straightening hair all have drawbacks. Thepermanent methods are typically time-consuming and may damage hair. Inaddition, such methods show little flexibility so that any need and/orwish for changing the hairstyle would require conducting again a“permanent” wave onto hair, which is time-consuming and further damagesthe hair.

Along with the high potential skin irritation during application,relaxers tend to permanently change the hair by breaking the naturaldisulfide bonds in the hair. This leaves the hair weaker and more pronefor further breakage. Over-processing can also increase hair damage andskin irritation. Consumer products using redox chemistry to achievesemi-permanent benefits, but overprocessing the hair and the strongsulphur smell are concerns of technologies based on reducing chemistry.

According to the US National Toxicology Program, formaldehyde is knownto be a human carcinogen. Therefore, providing a semi-permanent stylewith carcinogen-free formulation is paramount. Given the safety concernof formaldehyde and the damaging effect of relaxers and reducingchemistry, there is a need for a safe alternative to durablestraightening that does not break disulfide bonds.

None of the above methods allow achieving a hairstyle that may beretained and/or recovered after at least one shampoo treatment withoutseverely damaging the hair or using a carcinogenic active. There is aneed for the provision of a method for achieving a hairstyle that lastsat least five shampoo treatments so that the user would not need tore-shape hair after each shampoo but would still have the opportunity tochange hairstyle after some time and without needing to use stringent orharsh hair treatment, such as the permanent technologies outlined above.

WO2009/140076A1 states: a composition including an active materialhaving functional groups capable of covalent attachment to a substratein the presence of an acid or a base, a photocatalyst capable ofgenerating an acid or a base upon exposure to light, and a vehicle.WO2011/060110A1 states: a composition including an active materialhaving groups capable of covalent attachment to a substrate in thepresence of an acid or a base, a photocatalyst capable of generating anacid or a base upon exposure to light, and a vehicle. The active is asilicone polymer and/or a silicone oligomer, having a molecular weighthigher than 1,000 grams/mole, and at least one organic functional group.WO2010/126919A1 states: a composition treating a substrate characterizedby it comprising: (a) an active material that in the presence of an acidor a base has one or more functional groups forming covalent attachmentsto the non-physiological substrate's complementary functional groups;(b) a photocatalyst capable of generating an acid or a base uponexposure to light; and (c) a delivery vehicle for 1(a) and 1(b),alternatively a delivery vehicle being a solvent capable of dissolvingand dispersing the active material, alternatively a delivery vehicleselected from the group consisting of water, silicones, oils,hydrocarbons, lauryl sulfate salts and combinations thereof; wherein thesubstrates exclude physiological materials. There is a need thereforefor providing a method for achieving and semi-permanently retainingand/or recovering hairstyle using actives that do not break disulfidebonds (reducing agents) or that are considered carcinogenic. There isalso the need for providing a method for obtaining a hairstyleexhibiting resistance to shampoo treatments. Particularly, there is aneed for providing a method for retaining and/or recovering hairstyleafter at least one shampoo treatment, particularly after five shampootreatments, more particularly after ten shampoo treatments. In addition,there is a need for providing a method for achieving and retainingand/or recovering hairstyle, without damaging hair. Also, there is aneed for providing more economic semi-permanent hair straightening orhair relaxing treatments.

SUMMARY OF THE INVENTION

A first aspect of the invention relates to a method for shaping keratinfibres comprising:

-   -   (a) providing a crosslinking composition, wherein the        crosslinking composition comprises:        -   an active agent, wherein the active agent is selected from            the group consisting of:            2-hydroxypropane-1,2,3-tricarboxylic acid,            1,2,3,4-butanetetracarboxylic acid, a derivative thereof,            and mixtures thereof; and wherein the active agent has a            molecular weight of 500 g/mol or less;        -   a photocatalyst being a hydroxy-substituted aromatic            compound;        -   a cosmetically acceptable carrier;        -   wherein the crosslinking composition has not been exposed to            electromagnetic radiation having a wavelength of 750 nm or            less for 30 min or more;    -   (b) applying the crosslinking composition to keratin fibres,        mechanically shaping the keratin fibres with an appliance at a        temperature of from about 80° C. to about 180° C. and exposing        the composition to electromagnetic radiation having a wavelength        of from about 300 nm to about 750 nm.

A second aspect of the invention relates to a method for shaping keratinfibres comprising:

-   -   (a) providing a solid composition, wherein the solid composition        comprises:        -   an active agent, wherein the active agent is selected from            the group consisting of:            2-hydroxypropane-1,2,3-tricarboxylic acid,            1,2,3,4-butanetetracarboxylic acid, a derivative thereof,            and mixtures thereof; and wherein the active agent has a            molecular weight of about 500 g/mol or less;        -   a photocatalyst being a hydroxy-substituted aromatic            compound;        -   and then mixing the solid composition with a cosmetically            acceptable carrier to form a crosslinking composition;    -   (b) applying the composition to keratin fibres, mechanically        shaping the keratin fibres with an appliance at a temperature of        from about 80° C. to about 180° C. and exposing the composition        to electromagnetic radiation having a wavelength of from about        300 nm to about 750 nm.

A third aspect of the invention relates to a crosslinking compositionfor shaping keratin fibres comprising:

-   -   an active agent, wherein the active agent is selected from the        group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid,        1,2,3,4-butanetetracarboxylic acid, and mixtures thereof;    -   a photocatalyst being an hydroxy-substituted aromatic compound,        wherein the hydroxy-substituted aromatic compound is        multicyclic;    -   a cosmetically acceptable carrier.

A fourth aspect of the invention relates to the use of a crosslinkingcomposition for shaping keratin fibres comprising:

-   -   an active agent, wherein the active agent is selected from the        group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid,        1,2,3,4-butanetetracarboxylic acid, and mixtures thereof;    -   a photocatalyst being an hydroxy-substituted aromatic compound,        wherein the hydroxy-substituted aromatic compound is        multicyclic;    -   a cosmetically acceptable carrier.

A fifth aspect of the invention relates to a kit comprising:

-   -   (a) a crosslinking formulation comprising an active agent and        optionally a cosmetically acceptable carrier, wherein the active        agent is selected from the group consisting of:        2-hydroxypropane-1,2,3-tricarboxylic acid,        1,2,3,4-butanetetracarboxylic acid, and mixtures thereof;    -   (b) a photocatalyst formulation comprising a photocatalyst, and        wherein the photocatalyst is an hydroxy-substituted aromatic        compound, wherein the hydroxy-substituted aromatic compound is        multicyclic;    -   (c) optionally an appliance for mechanically shaping keratin        fibres;        wherein each of (a), (b) and (c) are separately packaged.

A sixth aspect of the invention relates to a process for forming acrosslinking composition, comprising mixing together:

-   -   an active agent, wherein the active agent is selected from the        group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid,        1,2,3,4-butanetetracarboxylic acid, and mixtures thereof; and    -   a photocatalyst being a hydroxy-substituted aromatic compound,        wherein the hydroxy-substituted aromatic compound is        multicyclic; and    -   a cosmetically acceptable carrier.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: Shows hair straightness analysis presented as a bar chart. The yaxis is the straightness score. Different treatment conditions aretested for a crosslinking composition comprising 5%2-hydroxypropane-1,2,3-tricarboxylic acid (citric acid), 200 ppmphotocatalyst and QSP water (buffered to pH10). Numbering along the xaxis: C=no crosslinking composition is used followed by hybrid heat andlight hair straightening irons at 250° F. (121° C.) and emitting UVlight at 380 nm; 1=hair switches are treated with crosslinkingcomposition and hybrid heat and light hair straightening irons at 250°F. (121° C.) and emitting UV light at 380 nm are used. The bars with thediagonal shading lines show the score by the expert grader after onewash-and-dry cycle and the bars with horizontal shading lines show thescore by the expert grader after 5 (i.e. 4 further) wash-and-dry cycles.

DETAILED DESCRIPTION OF THE INVENTION Definitions and General

In this document, including in all embodiments of all aspects of thepresent invention, the following definitions apply unless specificallystated otherwise. All percentages are by weight of the totalcomposition. All ratios are weight ratios. References to ‘parts’ e.g. amixture of 1 part X and 3 parts Y, is a ratio by weight. “QS” or “QSP”means sufficient quantity for 100% or for 100 g. +/− indicates thestandard deviation. All ranges are inclusive and combinable. The numberof significant digits conveys neither a limitation on the indicatedamounts nor on the accuracy of the measurements. All numerical amountsare understood to be modified by the word “about”. All measurements areunderstood to be made at 25° C. and at ambient conditions, where“ambient conditions” means at 1 atmosphere (atm) of pressure and at 50%relative humidity. “Relative humidity” refers to the ratio (stated as apercent) of the moisture content of air compared to the saturatedmoisture level at the same temperature and pressure. Relative humiditycan be measured with a hygrometer, in particular with a probe hygrometerfrom VWR® International. Herein: “min” means “minute” or “minutes”;“mol” means mole; “nanometers” is abbreviated “nm”; “g” following anumber means “gram” or “grams”. All weights as they pertain to listedingredients are based on the active level and do not include carriers orby-products that may be included in commercially available materials.Herein, “comprising” means that other steps and other ingredients can bein addition. “Comprising” encompasses the terms “consisting of” and“consisting essentially of”. The compositions, formulations, methods,uses, kits, and processes of the present invention can comprise, consistof, and consist essentially of the elements and limitations of theinvention described herein, as well as any of the additional or optionalingredients, components, steps, or limitations described herein.Embodiments and aspects described herein may comprise or be combinablewith elements, features or components of other embodiments and/oraspects despite not being expressly exemplified in combination, unlessan incompatibility is stated. “In at least one embodiment” means thatone or more embodiments, optionally all embodiments or a large subset ofembodiments, of the present invention has/have the subsequentlydescribed feature. Where amount ranges are given, these are to beunderstood as being the total amount of said ingredient in thecomposition, or where more than one species fall within the scope of theingredient definition, the total amount of all ingredients fitting thatdefinition, in the composition. For example, if the compositioncomprises from about 1% to about 5% fatty alcohol, then a compositioncomprising 2% stearyl alcohol and 1% cetyl alcohol, would fall withinthe scope.

“Molecular weight” or “M·Wt.” or “MW” and grammatical equivalents meanthe number average molecular weight.

“Viscosity” is measured at 25° C. using a HAAKE Rotation Viscometer VT550 with cooling/heating vessel and sensor systems according to DIN53019 at a shear rate of 12.9 s⁻¹.

“Water-soluble” refers to any material that is sufficiently soluble inwater to form a clear solution to the naked eye at a concentration of0.1% by weight of the material in water at 25° C. The term“water-insoluble” refers to any material that is not “water-soluble”.

“Substantially free from” or “substantially free of” means less thanabout 1%, or less than 0.8%, or less than 0.5%, or less than 0.3%, orabout 0%, by total weight of the composition or formulation.

“Keratin fibres” means fibrous material composed of keratin. “Hair”means mammalian keratin fibres including scalp hair, facial hair andbody hair. It includes such hair still being attached to a livingsubject and also hair that has been removed therefrom such as hairswatches and hair on a doll/mannequin. In at least one embodiment,“hair” means human hair. “Hair shaft” or “hair fibre” means anindividual hair strand and may be used interchangeably with the term“hair.”

“Cosmetically acceptable” means that the compositions, formulations orcomponents described are suitable for use in contact with humankeratinous tissue without undue toxicity, incompatibility, instability,allergic response, and the like. All compositions and formulationsdescribed herein which have the purpose of being directly applied tokeratinous tissue are limited to those being cosmetically acceptable.

“Derivatives” includes but is not limited to, amide, ether, ester,amino, carboxyl, acetyl, acid, salt and/or alcohol derivatives of agiven compound. In at least one embodiment, “derivatives thereof” meansthe amide, ether, ester, amino, carboxyl, acetyl, acid, salt and alcoholderivatives.

“Monomer” means a discrete, non-polymerised chemical moiety capable ofundergoing polymerisation in the presence of an initiator or anysuitable reaction that creates a macromolecule e.g. such aspolycondensation, polyaddition, anionic or cationic polymerization.“Unit” means a monomer that has already been polymerised i.e. is part ofa polymer.

“Polymer” means a chemical formed from the polymerisation of two or moremonomers. The term “polymer” shall include all materials made by thepolymerisation of monomers as well as natural polymers. Polymers madefrom only one type of monomer are called homopolymers. Herein, a polymercomprises at least two monomers. Polymers made from two or moredifferent types of monomers are called copolymers. The distribution ofthe different monomers can be random, alternating or block-wise (i.e.block copolymer). The term “polymer” used herein includes any type ofpolymer including homopolymers and copolymers.

“Kit” means a package comprising a plurality of components. “Kit” may bereferred to as “kit-of-parts”. An example of a kit is, for example, afirst composition and a separately packaged second composition andoptionally application instructions.

DESCRIPTION

The present invention relates inter alia to a method for shaping keratinfibres. The present method allows the achievement of a semi-permanenthairstyle i.e. a durable hairstyle, and semi-permanent shaping ofeyelashes. This semi-permanent hairstyle is retained after at least oneshampoo treatment, particularly after five shampoo treatments, moreparticularly after 10 shampoo treatments. Besides the increaseddurability of the hairstyle, this method prevents clumping of hairand/or improves post-shampoo detangling of hair and feel. In addition,the inventors have found that this method increases the water- andhumidity-resistance of the shape, increases the ease of style and/orincreases the manageability of the shape after shampooing. Withoutwishing to be bound by any theory, it is believed that the abovebenefits are due to the steps conducted, their sequence, as well as thespecific components used including the active agent. It is believed thatthe selected active agent diffuses into the shaft of the keratin fibre,reacts with hydroxyl groups to form crosslinks in the keratinpolypeptide, providing sufficient crosslinks to overcome the innaterestoring force of the keratin fibre structure. This results in adurable shaping of keratin fibres, for example a durable hairstyle ordurable eyelash shape.

The details of the different aspects of the invention are describedhereinafter. The present invention relates inter alia to a method forshaping keratin fibres. The method comprises providing a crosslinkingcomposition.

Crosslinking Composition

The crosslinking composition comprises an active agent. The active agentis useful for reacting with and providing crosslinks in keratin. Theactive agent is selected from the group consisting of:2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylicacid, a derivative thereof, and mixtures thereof. In at least oneembodiment, the active agent has a molecular weight of 400 g/mol orless. In at least one embodiment, the active agent has a molecularweight of 300 g/mol or less, or from about 50 g/mol to 250 g/mol, orfrom about 80 g/mol to about 150 g/mol. The molecular weight is usefulin view of penetration into the keratin fibers to crosslink it from theinside and not just superficially where the crosslink is more exposed toexternal factors. In the context of keratin fibres, the molecular weightis useful for penetration into the hair shaft i.e. under the cuticle.

In at least one embodiment, the active agent is liquid at 25° C. Activeagents being liquid at this temperature have the advantage of providingimproved hair feel versus active agents that are solid at thistemperature.

In at least one embodiment, the active agent is2-hydroxypropane-1,2,3-tricarboxylic acid. In at least one embodiment,the active agent is 1,2,3,4-butanetetracarboxylic acid.2-hydroxypropane-1,2,3-tricarboxylic acid and1,2,3,4-butanetetracarboxylic acid are available from Sigma Aldrich.

In at least one embodiment, the active composition comprises from about0.1% to about 40% active agent. In at least one embodiment, thecomposition comprises from about 0.5% to about 20%, or from about 0.1%to about 15%, or from about 1% to about 12%, or from about 5% to about15%, or from about 10% to about 12% active agent.

In at least one embodiment, the crosslinking composition furthercomprises a second active agent. The second active agent is useful forreacting with and providing further crosslinks in keratin. The haircomprises polypeptides of keratin having functional groups COOH, OH, andNH₂, and SH. Different active agents can react preferentially with eachfunctional group. For instance, arabinose preferentially reacts withamino groups whereas ethylene carbonate reacts preferentially with COOH.In at least one embodiment, the second active agent has at least twofunctional groups selected from the group consisting of: —NH₂, —NH—,—SH, —OH, —C(═O)H, —C═O, and —COOH; and wherein the second active agenthas a molecular weight of 500 g/mol or less. In at least one embodiment,the second active agent is a sugar. Sugars are useful because they arenaturally-derived, which is preferred by consumers versus syntheticcompounds. This is not only for perceived health and lack ofsensitisation reasons, but also for sustainability and environmentalreasons—sugars break down naturally and quickly and do not requirespecial disposal methods. Furthermore, sugars are also easy to sourceand relatively inexpensive. In at least one embodiment, the secondactive agent has a molecular weight of 500 g/mol or less. In at leastone embodiment, the second active agent has a molecular weight of 300g/mol or less, or from about 50 g/mol to 250 g/mol, or from about 80g/mol to about 150 g/mol. The molecular weight is useful in view ofpenetration into the keratin fibers to crosslink it from the inside andnot just superficially where the crosslink is more exposed to externalfactors. In the context of keratin fibres, the molecular weight isuseful for penetration into the hair shaft i.e. under the cuticle. In atleast one embodiment, the second active agent is liquid at 25° C. Secondactive agents being liquid at this temperature have the advantage ofproviding improved hair feel versus second active agents that are solidat this temperature.

In at least one embodiment, the crosslinking composition comprises atotal amount of active agent and wherein the total amount of activeagent is from about 0.1% to about 40% active agent.

In at least one embodiment, the crosslinking composition comprises acosmetically acceptable carrier. In at least one embodiment, thecosmetically acceptable carrier is any carrier suitable for formulatingthe crosslinking agent into a crosslinking composition being suitablefor application onto hair. In at least one embodiment, the cosmeticallyacceptable carrier is selected from either an aqueous medium or anaqueous-alcoholic medium. In at least one embodiment, when the carrieris an aqueous-alcoholic carrier, this carrier comprises water and analcohol. In at least one embodiment, the alcohol is selected from thegroup consisting of: ethanol, isopropanol, propanol, and mixturesthereof. In at least one embodiment, when the carrier is an aqueouscarrier, this carrier consists essentially of water and is substantiallyfree of alcohol. In at least one embodiment, the crosslinkingcomposition comprises a safe and effective amount of cosmeticallyacceptable carrier. In at least one embodiment, the crosslinkingcomposition comprises from about 0.1% to about 99%, or from about 1% toabout 98%, or from about 10% to about 97%, or from about 30% to about95% water.

The crosslinking composition comprises a photocatalyst being ahydroxy-substituted aromatic compound. A photocatalyst is an acid orbase (or conjugate thereof) having a pKa (or pKb) value that decreases(or increases) upon exposure to electromagnetic radiation, particularlylight. Photoacids are mentioned for example in Domcke and Sobolewski(2003), Unraveling the Molecular Mechanisms of Photoacidity, 302, p.1693 and in Kowalewska (2005), Photoacid catalyzed sol-gel process, J.Mater. Chem. 15, p. 4997, which are both incorporated herein byreference. In at least one embodiment, the electromagnetic radiation isselected from the group consisting of: ambient light, sunlight,incandescent light, fluorescent light, LED light, laser light, andcombinations thereof. In at least one embodiment, the electromagneticradiation is selected from the group consisting of: visible light, nearor far ultraviolet light, or near or far infrared light, andcombinations thereof. In at least one embodiment, the photocatalyst canbe activated to a photo-excited state by excitation with incidentradiation with a wavelength from about 300 nm to about 750 nm andwherein the appliance emits radiation with a wavelength from about 300nm to about 750 nm.

In at least one embodiment, the hydroxy-substituted aromatic compound isa quinoline compound or a naphthol compound. In at least one embodiment,the hydroxy-substituted aromatic compound is a fluorescein or aderivative thereof. In at least one embodiment, the hydroxy-substitutedaromatic compound is a halogen-substituted fluorescein. In at least oneembodiment, the hydroxy-substituted aromatic compound is bromo- oriodo-substituted fluorescein. In at least one embodiment, thehydroxy-substituted aromatic compound is selected from the groupconsisting of: diiodofluorescein,4,5,6,7-tetrachloro-2′,4′,5′,7′-tetraiodofluorescein (rose Bengal), asalt of 2,4,5,7-tetraiodofluorescein (erythrosine), Eosin Y, Eosin B,and mixtures thereof. In at least one embodiment, thehydroxy-substituted aromatic compound is a hydroxyflavone or aderivatives thereof. In at least one embodiment, the hydroxy-substitutedaromatic compound is a dihydroxyflavone or a trihydroxyflavone or atetrahydroxyflavone or a mixture thereof. In at least one embodiment,the hydroxy-substituted aromatic compound is selected from the groupconsisting of: 3-hydroxy flavones, 7-hydroxy flavones, 5,7-hydroxyflavones, 4′,5,7-trihydroxyflavone,2-(3,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-chromen-4-one (quercitin),and mixtures thereof. In at least one embodiment, thehydroxy-substituted aromatic compound is a hydroxyltriarylmethane, forexample FD&C Green 3. In at least one embodiment, thehydroxy-substituted aromatic compound is an anthocyanidins or ananthocyanin. In at least one embodiment, the hydroxy-substitutedaromatic compound is cyanidin (2-(3,4-dihydroxyphenyl)chromenylium-3,5,7-triol), malvidin, palargonidin or extracts containinganthocyanins such as elderberry, blueberry, cranberry, bilberry, redcabbage, sorghums, blackberry, black current, cherry red and blackraspberry, and mixtures thereof.

In at least one embodiment, the hydroxy-substituted aromatic compound isselected from the group consisting of: 8-hydroxyquinoline,8-hydroxyquinoline sulfate, 8-quinolinol-1-oxide, 5-hydroxyquinoline,6-hydroxyquinoline, 7-hydroxyquinoline,5-iodo-7-sulfo-8-hydroxyquinoline, 5-fluoro-8-hydroxyquinoline,5-fluoro-7-chloro-8-hydroxyquinoline,5-fluoro-7-bromo-8-hydroxyquinoline, 5-fluoro-7-iodo-8-hydroxyquinoline,7-fluoro-8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline,5,7-dichloro-8-hydroxyquinoline, 5-chloro-7-brono-8-hydroxyquinoline,5-chloro-7-iodo-8-hydroxyquinoline, 7-chloro-8-hydroxyquinoline,5-bromo-8-hydroxyquinoline, 5-bromo-7-chloro-8-hydroxyquinoline,5,7-dibromo-8-hydroxyquinoline, 5-bromo-7-iodo-8-hydroxyquinoline,7-bromo-8-hydroxyquinoline, 5-iodo-8-hydroxyquinoline,5-iodo-7-chloro-8-hydroxyquinoline, 5,7-diiodo-8-hydroxyquinoline,7-iodo-8-hydroxyquinoline, 5-sulfonic acid-8-hydroxyquinoline,7-sulfonic acid-8-hydroxyquinoline, 5-sulfonicacid-7-iodo-8-hydroxyquinoline, 5-thiocyano-8-hydroxyquinoline,5-chloro-8-hydroxyquinoline, 5-bromo-8-hydroxyquinoline,5,7-dibromo-8-hydroxyquinoline, 5-iodo-8-hydroxyquinoline,5,7-diiodo-8-hydroxyquinoline, 7-azaindole, 7-cyano-2-naphthol,8-cyano-2-naphthol, 5-cyano-2-naphthol,1-hydroxy-3,6,8-pyrenetrisulfonic acid, Trans-3-hydroxystilbene,2-hydroxymethylphenol, Pelargonidin, and mixtures thereof. In at leastone embodiment, the hydroxy-substituted aromatic compound is selectedfrom the group consisting of: 8-quinolinol-1-oxide, 8-hydroxyquinoline,7-cyano-2-naphthol, 8-cyano-2-naphthol, 5-cyano-2-naphthol, and mixturesthereof. In at least one embodiment, the hydroxy-substituted aromaticcompound is selected from the group consisting of: 8-quinolinol-1-oxide,8-hydroxyquinoline, and mixtures thereof. In at least one embodiment,the hydroxy-substituted aromatic compound is 8-hydroxyquinoline.8-hydroxyquinoline may act as a photoacid catalyst in lower pH solutionsor as a photobase catalyst in higher pH solutions. 8-hydroxyquinolinehas the CAS Number 148-24-3 and is available from Sigma-Aldrich. In atleast one embodiment, the hydroxy-substituted aromatic compound ismulti-cyclic. 8-hydroxyquinoline has the advantage of being easilyavailable and characterised for use in cosmetic compositions such ashair dye compositions.

In at least one embodiment, the crosslinking composition comprises fromabout 10 ppm to about 500 ppm photocatalyst being a hydroxy-substitutedaromatic compound. The concentration of photocatalyst may dependent, inpart, on a variety of factors including, for example, the chemicalstructure of the photocatalyst, the reaction medium, the reaction type,and the substrate. In at least one embodiment, the crosslinkingcomposition comprises from about 20 ppm to about 500 ppm, or from about30 ppm to about 450 ppm, or from about 30 ppm to about 400 ppm, or fromabout 50 ppm to about 350 ppm, or from about 70 ppm to about 330 ppm, orfrom about 80 ppm to about 310 ppm, or from about 90 ppm to about 300ppm, or from about 100 ppm to about 290 ppm, or to about 260 ppm, or toabout 250 ppm, or to about 240 ppm, or to about 220 ppm, or to about 210ppm, or to about 200 ppm photocatalyst being a hydroxy-substitutedaromatic compound. To note: 1 ppm=1 parts per million=1×10⁻⁴%=0.0001%and 10 ppm=1×10⁻³%=0.001% and 100 ppm=1×10⁻²%=0.01%.

The crosslinking composition has not been exposed to electromagneticradiation having a wavelength of 750 nm or less and for 30 min or more.The exposure of the crosslinking composition is important in view of theefficacy of the photocatalyst since when it is exposed toelectromagnetic radiation within a certain wavelength range it willreact with surround molecules if they are available, including compoundsin the packaging wall. In at least one embodiment, the crosslinkingcomposition is packaged in a container where electromagnetic radiationhaving a wavelength of 750 nm or less is not able to contact thecrosslinking composition. In at least one embodiment, the crosslinkingcomposition has not been exposed to electromagnetic radiation having awavelength of 750 nm or less, or from about 300 nm to about 750 nm, orvisible light, or UV light, and for 20 min or more, or 10 min or more,or 2 min or more. In at least one embodiment, the crosslinkingcomposition is packaged in an opaque container. In at least oneembodiment, the crosslinking composition is packaged in an amber- orbrown-coloured container.

Other ingredients may be present in the crosslinking composition. In atleast one embodiment, the crosslinking composition comprisesantioxidant. Antioxidant is useful in view of providing longer-termstability for the crosslinking composition. In at least one embodiment,the crosslinking composition comprises a safe and effective amount of anantioxidant. In at least one embodiment, the crosslinking compositioncomprises from about 0.001% to about 5%, or from about 0.5% to about1.0% antioxidant. In at least one embodiment, the antioxidant isselected from the group consisting of: ascorbic acid (vitamin C),ascorbyl esters of fatty acids, ascorbic acid derivatives (e.g.,magnesium ascorbyl phosphate, sodium ascorbyl phosphate, ascorbylsorbate), tocopherol (vitamin E), tocopherol sorbate, tocopherolacetate, other esters of tocopherol, butylated hydroxy benzoic acids andtheir salts, peroxides including hydrogen peroxide, perborate,thioglycolates, persulfate salts,6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (commerciallyavailable under the tradename Trolox™), gallic acid and its alkylesters, especially propyl gallate, uric acid and its salts and alkylesters, sorbic acid and its salts, lipoic acid, amines (e.g.,N,N-diethylhydroxylamine, amino-guanidine), sulfhydryl compounds (e.g.,glutathione), dihydroxy fumaric acid and its salts, lycine pidolate,arginine pilolate, nordihydroguaiaretic acid, bioflavonoids, curcumin,lysine, 1-methionine, proline, superoxide dismutase, silymarin, teaextracts, grape skin and/or grape seed extracts, melanin, rosemaryextracts, and mixtures thereof. In at least one embodiment, theantioxidant is tocopherol sorbate or an ester of tocopherol. Forexample, the use of tocopherol sorbate in topical compositions andapplicable to the present invention is described in U.S. Pat. No.4,847,071, issued on Jul. 11, 1989 to Donald L. Bissett, Rodney D. Bushand Ranjit Chatterjee. In at least one embodiment, the antioxidant issodium benzoate. In at least one embodiment, the antioxidant is ascorbicacid. Ascorbic acid has the benefit of enhancing the oxidative stabilityof the formulation. In at least one embodiment, the crosslinkingcomposition comprises a safe and effective amount of ascorbic acid. Inat least one embodiment, the crosslinking composition comprises fromabout 0.001% to about 5%, or from about 0.5% to about 1.0% ascorbicacid.

In at least one embodiment, the crosslinking composition comprises achelator or chelating agent. As used herein, “chelator” or “chelatingagent” means an active agent capable of removing a metal ion from asystem by forming a complex so that the metal ion cannot readilyparticipate in or catalyze chemical reactions. The inclusion of achelating agent is especially useful for providing protection against UVradiation which can contribute to excessive scaling or skin texturechanges and against other environmental agents which can cause skindamage, in order to decrease the local iron load, which generates, asindicated above, a pro-oxidant situation and pigmentation. A chelatingagent is useful in view of providing longer-term stability for thecrosslinking composition. In at least one embodiment, the crosslinkingcomposition comprises a safe and effective amount of a chelator orchelating agent. In at least one embodiment, the crosslinkingcomposition comprises a chelating agent, and wherein the chelating agentis selected from the group consisting of: N-hydroxysuccinimide, EDTA,NTA, deferoxamine, hydroxamic acids and their salts, phytic acid,phytate, gluconic acid and its salts, transferrine, lactoferrin, andmixtures thereof. In at least one embodiment, the crosslinkingcomposition comprises a safe and effective amount of chelating agent. Inat least one embodiment, the crosslinking composition comprises fromabout 0.001% to about 10%, or from about 0.01% to about 5%, or fromabout 0.1% to about 5%, or from about 0.5% to about 1.0% chelatingagent. Exemplary chelators that are useful herein are disclosed in U.S.Pat. No. 5,487,884, issued Jan. 30, 1996 to Bissett et al.;International Publication No. 91/16035, Bush et al., published Oct. 31,1995; and International Publication No. 91/16034, Bush et al., publishedOct. 31, 1995. In at least one embodiment, the chelating agent isselected from the group consisting of: N-hydroxysuccinimidedeferoxamine, lactoferrin, hydroxamic acids, gluconic acid, phytic acid,derivatives thereof, and mixtures thereof.

In at least one embodiment, the crosslinking composition is in a formsuitable for application onto hair. In at least one embodiment, thecrosslinking composition is in the form of an emulsion, a solution, or adispersion. In at least one embodiment, the crosslinking compositioncomprises a surfactant. The surfactant can be useful in providing anemulsion. In at least one embodiment, when being in the form of anemulsion, said emulsion may be a water-in-oil emulsion, an oil-in-wateremulsion, or a multiple emulsion. An emulsion has the benefit ofproviding an easy-to-apply composition for the consumer to apply to thehair and has aesthetic advantages. The crosslinking composition may be aleave-in composition or a rinse-off composition. The crosslinkingcomposition may be in a form selected from: a shampoo; a hairconditioning composition; a hairstyling composition; or combinationsthereof. When being a hairstyling composition, said composition may be agel composition; a spray gel composition, optionally dispensed using amechanical spray device and/or at least one propellant; a non-aerosolhairspray, optionally dispensed using a suitable mechanically operatedspraying device; a foamable composition, optionally dispensed usingdevices for foaming; hair wax composition; hair lotion composition; haircream composition; or combinations thereof. In at least one embodiment,the crosslinking composition is a mascara composition.

The crosslinking composition may further comprise at least one cosmetichair treatment agent selected from hairstyling polymers, conditioningagents, hair cleansing agents, or mixtures thereof. In at least oneembodiment, the crosslinking composition comprises a hairstylingpolymer. In at least one embodiment, the hairstyling polymer is selectedfrom the group consisting of: non-ionic hairstyling polymer, anionichairstyling polymer, zwitterionic and/or amphoretic hairstyling polymer,cationic hair styling polymer, or mixtures thereof. Suitable hairstylingpolymers may be found in the CTFA International Cosmetics IngredientDictionary and Handbook, “Hair Fixatives”, 12^(th) edition (2008).Suitable hairstyling polymers are, for example, those materialsdisclosed from page 12, line 5 to page 19, line 1 of the European patentapplication 08151246.9 filed on 11 Feb. 2008, which is incorporatedherein by reference.

In at least one embodiment, the crosslinking composition comprises fromabout 0.01% to about 10% by weight, or from about 0.1% to about 8%, orfrom about 0.1% to about 5% hairstyling polymer.

In at least one embodiment, the crosslinking composition comprises anon-ionic hairstyling polymer. In at least one embodiment, the non-ionichairstyling polymer is a natural or synthetic polymer. In at least oneembodiment, the non-ionic hair styling polymers is a polymer obtainedfrom the polymerisation of at least one type of monomer selected from:vinylpyrrolidone; vinylcaprolactam; vinyl esters; vinyl alcohol; vinylacetate; (meth)acrylamide, and/or its derivatives; (meth)acrylic acid,its salts, and/or its derivatives; propylene and/or ethylene glycolacid; crotonic acid; or mixtures thereof. For example, such polymers areavailable under the trade names Luviskol® or Luviset Clear®.

In at least one embodiment, the crosslinking composition comprises ananionic hairstyling polymer. In at least one embodiment, the anionichairstyling polymer is selected from the group consisting of: acrylicacid/alkyl acrylate/Nalkylacrylamide terpolymer; vinyl acetate/crotonicacid copolymer; C1-C5-alkyl acrylate/(meth)acrylic acid copolymer;sodium polystyrenesulfonate; vinyl acetate/crotonic acid/vinyl alkanoatecopolymer; vinyl acetate/crotonic acid/vinyl neodecanoate copolymer;aminomethylpropanol acrylate copolymer; vinylpyrrolidone/(meth)acryliccopolymer; methyl vinyl ether/maleic monoalkyl esters copolymer;aminomethylpropanol salts of allyl methacrylate/(meth)acrylatecopolymer; ethyl acrylate/methacrylic acid copolymer; vinylacetate/mono-nbutyl maleate/isobornyl acrylate copolymer;octylacrylamid/(meth)acrylic acid copolymer; polyesters of diglycol,cyclohexanedimethanol, isophthalic acid and sulfoisophthalic acid; andmixtures thereof.

In at least one embodiment, the crosslinking composition comprises azwitterionic or amphoteric hairstyling polymer. In at least oneembodiment, the zwitterionic or amphoteric hairstyling polymer isselected from the group consisting of: alkylacrylamide/alkylaminoalkylmethacrylate/(meth)acrylic acid copolymers; copolymers which are formedfrom at least one first monomer type which has quaternary amine groups,and at least one second monomer type which has acid groups; copolymersof fatty alcohol acrylates, of alkylamine oxide methacrylate and atleast one monomer chosen from acrylic acid and methacrylic acid;methacryloylethylbetaine/methacrylic acid and/or esters copolymers;polyquaternium-47; polyquaternium-43; oligomers or polymers, preparablefrom quaternary croton betaines or quaternary croton betaine esters; ormixtures thereof.

In at least one embodiment, the crosslinking composition comprises acationic hairstyling polymer. In at least one embodiment, the cationichairstyling polymer is selected from the group consisting ofhomopolymers or copolymers where a quaternary nitrogen groups arepresent either in the polymer chain or as substituent on one or more ofthe cationic monomers. The monomers containing ammonium groups may becopolymerized with non-cationic monomers. Suitable cationic monomers maybe unsaturated, free-radically polymerizable compounds which carry atleast one cationic group, in particular ammonium-substituted vinylmonomers, such as, for example, trialkylmethacryloxyalkylammonium,trialkylacryloxyalkylammonium, dialkyldiallylammonium and quaternaryvinylammonium monomers with cyclic, cationic nitrogen-containing groups,such as pyridinium, imidazolium or quaternary pyrrolidones, e.g.alkylvinylimidazolium, alkylvinylpyridinium, or alkylvinylpyrrolidonesalts. The alkyl groups of these monomers are preferably lower alkylgroups, such as, for example, C1 to C7-alkyl groups, particularlypreferably C1 to C3-alkyl groups. Suitable non-cationic monomers may beselected from (meth)acrylamide, derivatives thereof; acrylate, itsderivative thereof; vinylcaprolactone, vinylcaprolactam,vinylpyrrolidone, vinyl esters, vinyl alcohol, propylene glycol orethylene glycol. For example, suitable cationic hairstyling polymers areavailable under the tradenames Gafquat 755 N; Gafquat 734; Gafquat HS100; Luviquat HM 550; Merquat Plus 3300; Gaffix VC 713; Aquaflex SF 40.In at least one embodiment, the crosslinking composition comprises acationic hairstyling polymer derived from a natural polymer. In at leastone embodiment, the cationic hairstyling polymer derived from a naturalpolymer is derived from a natural polymer selected from the groupconsisting of: cationic derivatives polysaccharides such as cellulose,starch and/or guar; chitosan, its salts, and/or its derivatives; ormixtures thereof. In at least one embodiment, the cationic hairstylingpolymers are selected from the group consisting of: polyquaternium-4;polyquaternium-10; polyquaternium-24; guar hydroxypropyltrimoniumchloride; chitosonium pyrrolidonecarboxylate; and mixtures thereof.

In at least one embodiment, the crosslinking composition comprises aconditioning agent, or a hair conditioning agent. The crosslinkingcomposition may comprise any suitable and conventional hair conditioningagents. The term “hair conditioning agent” herein means any cosmeticallyacceptable compound having a cosmetic effect on hair, such as providinggloss to hair, making hair more manageable, improving hair touch,improving combability and/or giving hair more volume. Suitable hairconditioning agents may be found in the CTFA International CosmeticsIngredient Dictionary and Handbook, “Hair conditioning agents”, 12^(th)edition (2008). In at least one embodiment, the hair conditioning agentis selected from the group consisting of: cationic surfactants,non-ionic surfactants, silicone compounds, organic oily conditioningagents, and mixtures thereof. Suitable hair conditioning agents are, forexample, those materials disclosed from page 19, line 3 to page 27, line33 of the European patent application 08151246.9 filed on 11 Feb. 2008,which is incorporated herein by reference.

In at least one embodiment, the conditioning agent is a cationicsurfactant. In at least one embodiment, the cationic surfactantcomprises amino or quaternary ammonium moieties. In at least oneembodiment, the crosslinking composition comprises from about 0.05% toabout 3.5%, or from about 0.1% to about 3.0%, or from about 0.5% toabout 2.5%, or from about 1.0% to about 2.0% cationic surfactant. In atleast one embodiment, cationic surfactant is according to Formula II:

wherein at least one of R⁷¹, R⁷², R⁷³ and R⁷⁴ is selected from: analiphatic group of from 8 to 30 carbon atoms; an aromatic, alkoxy,polyoxyalkylene, alkylamido, hydroxyalkyl, aryl; or an alkylaryl grouphaving from 7 to 22 carbon atoms; wherein the remainder of R⁷¹, R⁷², R⁷³and R⁷⁴ are independently selected from the group consisting of: analiphatic group consisting of from 1 to 22 carbon atoms; and anaromatic, alkoxy, polyoxyalkylene, alkylamido, hydroxyalkyl, aryl oralkylaryl group having up to 22 carbon atoms; wherein X is selected fromthe group consisting of: halogen, acetate, citrate, lactate, glycolate,phosphate, nitrate, sulfonate, sulfate, alkylsulfate, alkyl sulfonateradicals, and mixtures thereof. In at least one embodiment, cationicsurfactant is according to Formula II (see above), wherein at least oneof R⁷¹, R⁷², R⁷³ and R⁷⁴ is an aliphatic group having from 16 to 24carbon atoms; wherein the remainder of R⁷¹, R⁷², R⁷³ and R⁷⁴ areindependently selected from the group consisting of aliphatic groupshaving from 1 to 4 carbon atoms; wherein X is selected from the groupconsisting of: chloride or sulfate. In at least one embodiment, thecationic surfactant is selected from the group consisting of:behenyltrimethylammonium chloride, methyl sulfate or ethyl sulfate;stearyltrimethylammonium chloride, methyl sulfate or ethyl sulfate; andmixtures thereof. It is believed that a longer alkyl group providesimproved smoothness and soft feeling on wet and dry hair, compared tocationic surfactants with a shorter alkyl group. It is also believedthat such cationic surfactants can provide reduced scalp irritation,compared to those having a shorter alkyl group. In at least oneembodiment, the cationic surfactant is a di-long alkyl quaternizedammonium salt selected from the group consisting of: dialkyl (14-18carbons) dimethyl ammonium chloride, ditallow alkyl dimethyl ammoniumchloride, dihydrogenated tallow alkyl dimethyl ammonium chloride,distearyl dimethyl ammonium chloride, dicetyl dimethyl ammoniumchloride, and mixtures thereof. In at least one embodiment, the cationicsurfactant is a tertiary amidoamine having an alkyl group of from about12 to about 22 carbons. In at least one embodiment, the cationicsurfactant is selected from the group consisting of: cetyl trimethylammonium salts; behenyl trimethyl ammonium salts; dimethyl ditallowammonium salts; stearyl amidopropyl dimethylamine; (di)esterquats;quaternium 8, 14, 15, 18, 22, 24, 26, 27, 30, 33, 37, 53, 60, 61, 72,78, 80, 81, 82, 83, 84, and/or 91; or mixtures thereof.

In at least one embodiment, the conditioning agent is a non-ionicsurfactant. Suitable non-ionic surfactants may be surfactants having aHLB of less than 8. Suitable nonionic surfactants may be selected fromglyceryl esters; sugar esters; alkylpolyglucoside ethers; oleyl- orisostearylpolyglucoside; polyoxyethylene (20) sorbitan monostearate; ormixtures thereof.

In at least one embodiment, the conditioning agent is a siliconecompound. In at least one embodiment, the silicone compound is volatileor nonvolatile, and/or soluble or insoluble silicones. For example,suitable silicone conditioning agents are available under the tradenamesSF 1075 methyl phenyl fluid (Electric company); DC200 Fluid, DC244,DC245, DC345, Dow 5-7113, DC556 Cosmetic Grade Fluid, DC1248 (DowCorning). In at least one embodiment, the crosslinking compositioncomprises a conditioning agent being the reaction product of: (a) anaminosilane; (b); polysiloxane; and optionally (c) a polyether. In atleast one embodiment, the crosslinking composition comprises aconditioning agent being the reaction product of: (a) an aminosilane;(b); polysiloxane; and (c) a polyether. In at least one embodiment, thecrosslinking composition comprises a conditioning agent, and wherein theconditioning agent is selected from the group consisting of:epoxyaminosilane copolymers, and polysiloxane/polyurea block copolymers,and mixtures thereof. In at least one embodiment, the crosslinkingcomposition comprises a conditioning agent being the reaction productof: (a) an aminosilane; (b) polysiloxane; and (c) a polyether; andoptionally (d) an amine. In at least one embodiment, the polysiloxane isan epoxy encapped polysiloxane. In at least one embodiment, thepolysiloxane comprises at least two oxirane or oxetane groups. In atleast one embodiment, the polysiloxane comprises from about 10 to about450 silicon atoms, or from about 40 to about 400 silicon atoms, fromabout 75 to about 350 silicon atoms, from about 150 to about 250 siliconatoms. In at least one embodiment, the polysiloxane is an epoxy encappedpolysiloxane. In at least one embodiment, the polyether has the averagestructure CH₂(O)CHCH₂O(CH₂(CH₃)CH₂O)_(n)CH₂CH(O)CH₂ wherein n is aninteger from 1 to 10. In at least one embodiment, the amine comprisesfrom 1 to 10 carbon atoms, or from 2 to 5 carbon atoms. In at least oneembodiment, the amine is an alkylamine that is substituted with at leastone alkyl group. In at least one embodiment, the amine is selected fromthe group consisting of: methylamine, ethylamine, propylamine, ethanolamine, isopropylamine, butylamine, isobutylamine, hexylamine,dodecylamine, oleylamine, aniline aminopropyltrimethylsilane,aminopropyltriethylsilane, aminomorpholine, aminopropyldiethylaminebenzylamine, napthylamine 3-amino-9-ethylcarbazole,1-aminoheptaphlorohexane,2,2,3,3,4,4,5,5,6,6,7,7,8,8,8-pentadecafluoro-1-octanamine, and mixturesthereof. In at least one embodiment, the amine is selected from thegroup consisting of: methylethylamine, methylhexylamine,methyloctadecylamine, diethanolamine, dibenzylamine, dihexylaminedicyclohexylamine, piperidine, pyrrolidine phthalimide, and mixturesthereof. In at least one embodiment, the conditioning agent is anepoxyaminosilane copolymer. In at least one embodiment, the conditioningagent is conditioning agent being the reaction product of: (a) anaminosilane; (b) polysiloxane, wherein the polysiloxane comprises fromabout 10 to about 450 silicon atoms, or from about 40 to about 400silicon atoms; and (c) a polyether; and (d) an amine, wherein the amineis an alkylamine that is substituted with at least one alkyl group.Epoxyaminosilane copolymers are described in EP2214633B1 (filing date 30Oct. 2008, which is incorporated herein by reference) and are availablefrom Momentive™ Performance Materials Inc., Columbus, Ohio, USA.Epoxyaminosilane copolymers have excellent durability benefits. Such anexemplary expoxyaminosilane copolymer may be synthesised as follows:aminopropyltriisopropoxy silane (40.77 g), an epoxy encappedpolysiloxane with the average structureCH₂(O)CHCH₂OCH₂CH₂Si(CH₃)₂O[Si(CH₃)₂O]₅₀Si(CH₃)₂CH₂CH₂CH₂OCH₂CH(O)CH₂(171.40 g) and an epoxy endcapped polyether with the average structureCH₂(O)CHCH₂O(CH₂(CH₃)CH₂O)₇CH₂CH(O)CH₂ (37.83 g) and isopropanol (425.68g) is combined in a 500 mL flask. The material is brought to reflux andstirred with an overhead stirrer. The refluxing continued for 15.5 hruntil all epoxy groups are consumed as determined by titration. Thematerial is transferred to a rotary evaporator and stripped at 70° C.and 532 Pa (4 torr) for 2 hrs to remove the isopropanol. Anotherexemplary expoxyaminosilane copolymer may be synthesised as follows:aminopropyltriisopropoxy silane (14.27 g), 3-(diethylamino)propylamine(7.05 g), an epoxy encapped polysiloxane with the average structureCH₂(O)CHCH₂OCH₂CH₂CH₂Si(CH₃)₂O[Si(CH₃)₂O]₂₀₀Si(CH₃)₂CH₂CH₂CH₂OCH₂CH(O)CH₂(447.87 g) and an epoxy encapped polyether with the average structureCH₂(O)CHCH₂O(CH₂CH₂O)₁₄CH₂CH(O)CH₂ (30.81 g) and isopropanol (500 g) iscombined in a 2000 mL flask. The material is brought to reflux andstirred with an overhead stirrer. The refluxing continued for 24 hruntil all epoxy groups are consumed as determined by titration. Thematerial is transferred to a rotary evaporator and stripped at 70° C.and 532 Pa (4 torr) for 2 hrs to remove the isopropanol.

In at least one embodiment, the conditioning agent is selected from thegroup consisting of: epoxyaminosilane copolymers, andpolysiloxane/polyurea block copolymers, and mixtures thereof. Apolysiloxane/polyurea block copolymer is described in EP2074986B1 filedon 10 Dec. 2008, which is incorporated herein by reference. In at leastone embodiment, the polysiloxane/polyurea block copolymer comprises atleast one polysiloxane sequence (or block) and at least one polyureasequence (block) in the backbone of the copolymer. In at least oneembodiment, the amount of polysiloxane present in the copolymer isgreater than 90% by weight relative to the total weight of thepolysiloxane/polyurea block copolymer. In at least one embodiment, thepolysiloxane/polyurea block copolymer of the does not comprisepolyurethane. By way of non-limiting example, the copolymer can be anon-ionic polysiloxane/polyurea copolymer, that is to say that it doesnot comprise an ionized or ionizable group. By way of example of acopolymer, non-limiting mention may be made of thedimethylpolysiloxane/polyurea block copolymer having the INCI namepolyureadimethicone. Such a dimethylpolysiloxane/polyurea blockcopolymer can be obtained, for instance, by copolymerization of anα,ω-aminosilicone with a diisocyanate. Polysiloxane/polyurea blockcopolymers corresponding to these characteristics are, for example, theproducts sold under the reference Wacker-Belsil® UD 60, Wacker-Belsil®UD 80, Wacker-Belsil® DU 140 and Wacker-Belsil® UD 200 by Wacker. In atleast one embodiment, the polysiloxane/polyurea copolymer is non-ionic.In at least one embodiment, the crosslinking composition comprises fromabout 0.05 to about 20%, for example from 0.1 to 15%, or from 0.5 to 10%polysiloxane/polyurea block copolymer.

In at least one embodiment, the conditioning agent is an organic oilyconditioning agent. In at least one embodiment, the organic oilyconditioning agent is non-volatile, water-insoluble, oily or fatty.Organic oily conditioning agents may be selected from hydrocarbon oilsand fatty esters. In at least one embodiment, the conditioning agent isa fatty alcohol. In at least one embodiment, the fatty alcohol is anon-volatile low melting point fatty alcohol. In at least oneembodiment, the conditioning agent is a fatty alcohol and the fattyalcohol is selected from the group consisting of: capryl alcohol, laurylalcohol, stearyl alcohol, cetyl alcohol, myristyl alcohol, palmitoleylalcohol, and mixtures thereof.

The crosslinking composition may further comprise at least one directhair dye. In at least one embodiment, the crosslinking compositioncomprises from about 0.01% to about 15%, or from about 0.1% to about10%, or from about 0.5% to about 8% direct hair dye.

The crosslinking composition may further comprise at least oneviscosity-modifying agent. In at least one embodiment, the crosslinkingcomposition comprises from about 0.01% to about 20%, or from about 0.05%to about 10%, or from about 0.1% to about 5% viscosity-modifying agent.

The crosslinking composition may further comprise at least oneemulsifier and/or surfactant. In at least one embodiment, the emulsifierand/or surfactant is selected from nonionic surfactants; anionicsurfactants; amphoretic surfactants; or mixtures thereof. In at leastone embodiment, the crosslinking composition comprises from about 0.01%to about 20%, or from about 0.05% to about 10%, or from about 0.1% toabout 5%, emulsifier and/or surfactant.

The crosslinking composition may further comprise at least one pigment.In at least one embodiment, the pigment is selected from naturalpigments; synthetic pigments; or mixtures thereof. The pigments may beselected from organic pigment, inorganic pigment; or mixtures thereof.The pigments may be selected from coloured pigments; pearlescentpigments; or mixtures thereof. Said crosslinking composition maycomprise from about 0.01% to 10%, or from about 1% to about 2% pigmentpresent in the product mass in undissolved form by weight of the totalcrosslinking composition. The crosslinking composition may comprisepigment materials such as inorganic, nitroso, monoazo, disazo,carotenoid, triphenyl methane, triaryl methane, xanthene, quinoline,oxazine, azine, anthraquinone, indigoid, thionindigoid, quinacridone,phthalocianine, botanical, natural colors, including: water-solublecomponents such as those having C.I. Names.

In at least one embodiment, the crosslinking composition comprises atleast one particulate substance. In at least one embodiment, theparticulate substance is selected from silica; silicates; aluminates;clay earths; mica; insoluble salts, particularly insoluble inorganicmetal salts; metal oxides; minerals; insoluble polymer particles; ormixtures thereof. In at least one embodiment, the crosslinkingcomposition comprises from about 0.01% to about 10%, or from about 0.05%to about 5% of at least one particulate substance. In at least oneembodiment, the crosslinking composition is substantially free of aparticulate substance such as clay.

In at least one embodiment, the crosslinking composition comprises atleast one preservative. In at least one embodiment, the crosslinkingcomposition may comprise from about 0.01% to about 5% by weight, or fromabout 0.05% to about 1% preservative.

A variety of additional optional ingredients may be incorporated intothe crosslinking composition of the present invention. Non-limitingexamples of these additional ingredients may be selected frompreservatives; antioxidants; sequestering agents; solvents; fragrances &perfumes; fillers; screening agents; odour absorbers; colouringmaterials; lipid vesicles; detersive surfactants; thickening agents andsuspending agents; viscosity modifiers; pearlescent aids; UV-filters andsunscreens; agents for combating free radicals; polyvinyl alcohol; pHadjusting agents; salts; colouring agents; polymer plasticizing agents;direct dyes; or mixtures thereof. The crosslinking composition maycomprise from about 0%, or from about 0.1% to about 5% antimicrobialagents. In at least one embodiment, the crosslinking compositioncomprises an organic acid selected from the group consisting of:glycine, L-methionine, L-arginine, biotin, creatine, and mixturesthereof. In at least one embodiment, the crosslinking compositioncomprises an antidandruff agent. In at least one embodiment, thecrosslinking composition comprises zinc pyrithione. In at least oneembodiment, the crosslinking composition comprises panthenol. In atleast one embodiment, the crosslinking composition comprises a waxcompound. In at least one embodiment, the crosslinking compositioncomprises beeswax.

In at least one embodiment, the crosslinking composition has aviscosity, measured at 25° C., of from about 0.1 mPa·s to about1,000,000 mPa·s, or from about 1 mPa·s to about 80,000 mPa·s, or fromabout 5 mPa·s to about 3,500 mPa·s. The viscosity is measured by HAAKERotation Viscometer VT 550 with cooling/heating vessel and sensorsystems according to DIN 53019 (MV-DIN, SV-DIN), shear rate is 12.9 s⁻¹.

In at least one embodiment, the crosslinking composition issubstantially free of: formaldehyde, derivatives of formaldehyde,methylene glycol, formalin, and any compound that produces formaldehydeupon heating. “Heating” means raising the temperature of the compoundabove 25° C. In at least one embodiment, the crosslinking compositioncomprises 0% formaldehyde. In at least one embodiment, the derivativesof formaldehyde are 1,3,5-trioxane and paraformaldehyde. In at least oneembodiment, the crosslinking composition is substantially free of:formaldehyde, 1,3,5-trioxane, paraformaldehyde, methylene glycol,formalin. Formaldehyde is not preferred in view of its safety profile.Formalin is not advantageous because formalin is a derivative offormaldehyde. Formaldehyde exists in multiple forms. In water,formaldehyde becomes hydrated and forms methylene glycol. A saturatedsolution of formaldehyde (about 40% formaldehyde) in water is morecommonly known as formalin Methanol and/or methylene diol can be used asa stabilizer in formalin and is therefore not advantageous. In at leastone embodiment, the crosslinking composition is substantially free of aquaternary ammonium compound and/or a surfactant. In at least oneembodiment, the crosslinking composition is substantially free of:ceramide compound, an alpha-hydroxy acid, a thioglycolate and/orthiolactate compound, a bisulfate compound, clay, a reducing agent. Inat least one embodiment, the crosslinking composition is substantiallyfree of: ceramide compound, an alpha-hydroxy acid, a thioglycolateand/or thiolactate compound, a bisulfate compound. In at least oneembodiment, the crosslinking composition is substantially free of acarbonate compound. In at least one embodiment, the crosslinkingcomposition is substantially free of: ceramide compound, analpha-hydroxy acid, a thioglycolate or thiolactate compound, a bisulfatecompound, clay, formaldehyde, 1,3,5-trioxane, paraformaldehyde,methylene glycol, quaternary ammonium compound, surfactant.

In at least one embodiment, the crosslinking composition has a pH offrom about pH 2 to about pH 11. In at least one embodiment, thecrosslinking composition has a pH of from about pH 2 to about pH 6.5, offrom about pH 3 to about pH 5, or from about pH 3 to about pH 4. In atleast one embodiment, the crosslinking composition comprises a bufferingagent. In at least one embodiment, the buffering agent is a phosphatebuffer. In at least one embodiment, the buffering agent is a boratebuffer or a carbonate buffer. In at least one embodiment, the bufferingagent is selected from the group consisting of: glycine/sodiumhydroxide; sodium carbonate/sodium hydrogen carbonate, sodiumtetraborate/sodium hydroxide; sodium bicarbonate/sodium hydroxide;ammonium chloride/ammonia. The buffering agent has the advantage ofcontrolling the pH, which aids the stability of the crosslinkingcomposition. In at least one embodiment, the crosslinking compositioncomprises an alkalizing agent and/or an agent for adjusting the pHvalue. The crosslinking composition may further comprise a protonatingagent. The protonating agent may be a monoprotic or polyprotic acid,water-soluble or water-insoluble acid, and/or an organic or inorganicacid. In at least one embodiment, the protonating agent is selected fromformic acid, acetic acid, sulfuric acid, hydrochloric acid, citric acid,and mixtures thereof. In at least one embodiment, the protonating agentis citric acid. Citric acid is useful because it is naturally availablefrom lemons.

Method

The first aspect and the second aspect relate to a method for shapingkeratin fibres. In at least one embodiment, the method does not comprisea rinsing step between step (a) and step (b). It is not helpful for theefficacy of the invention if the active agent and photocatalyst arewashed off the keratin fibres prior to exposing the composition toelectromagnetic radiation. In at least one embodiment, the mechanicalshaping of keratin fibres is selected from the group consisting of:straightening keratin fibres, such as human scalp hair or humaneyelashes, and curling keratin fibres, such as human scalp hair or humaneyelashes.

The method comprises applying the crosslinking composition to keratinfibres. Further detail on embodiments and description of thecrosslinking composition is provided above. In at least one embodiment,the crosslinking composition remains on the keratin fibres for a time X,wherein time X is from about 2 min to about 60 min, or from about 5 minto about 30 min.

The method uses an appliance or implement. In at least one embodiment,the appliance is a hair straightening appliance comprising a heatingelement. In at least one embodiment, the appliance is a hair curlingappliance comprising a heating element. In at least one embodiment, theappliance is a hair straightening appliance comprising a heating elementand a source of electromagnetic radiation for exposing hair toelectromagnetic radiation. In at least one embodiment, the implement isa combing or brushing means and the crosslinking composition is exposedto electromagnetic radiation having a wavelength of from about 300 nm toabout 750 nm using a separate source of electromagnetic radiation suchas a lamp. In at least one embodiment, the appliance compriseslight-emitting diodes.

The crosslinking composition is exposed to electromagnetic radiationhaving a wavelength of from about 300 nm to about 750 nm. In at leastone embodiment, the electromagnetic radiation has a wavelength of fromabout 310 nm, or from about 320 nm, or from about 330 nm, or from about340 nm, or from about 350 nm, or from about 360 nm, or from about 370nm, or from about 380 nm, or from about 390 nm, or from about 400 nm, orfrom about 410 nm, to about 740 nm, or to about 730 nm, or to about 720nm, or to about 710 nm, or to about 700 nm, or to about 690 nm, or toabout 680 nm, or to about 670 nm, or to about 650 nm, or to about 640nm. In at least one embodiment, the electromagnetic radiation has awavelength of from 380 nm to about 550 nm.

Irradiance, that is the power of electromagnetic radiation in Watts perunit area, has the unit Watts per m² or W/m². Irradiance is thus ameasurement of the intensity of electromagnetic radiation. Lightintensity can also be measured in lux (lx), which is the unit ofilluminance. 1 lx=about 1.5×10⁻⁷ W/cm² (at 555 nm). An averagelaboratory or office space would have a light intensity of about 200 lxto about 1000 lx i.e. an irradiance of about 2.9×10⁻⁵ W/cm² to about1.4×10⁻⁴ W/cm² (at 555 nm). In at least one embodiment, theelectromagnetic radiation has an irradiance of at least about 1×10⁻³W/cm², or at least about 5×10⁻³ W/cm², or at least about 1×10⁻² W/cm²,or at least about 5×10⁻² W/cm², or at least about 1×10⁻¹ W/cm², or atleast about 5×10⁻¹ W/cm². In at least one embodiment, theelectromagnetic radiation has an illuminance of at least about 1000 lx,or at least about 2000 lx, or at least about 3000 lx, or at least about4000 lx, or at least about 5000 lx, or at least about 6000 lx, or atleast about 7000 lx, or at least about 8000 lx, or at least about 9000lx, or at least about 10000 lx, or at least about 20000 lx, or at leastabout 30000 lx, or at least about 40000 lx, or at least about 50000 lx,or at least about 60000 lx, or at least about 70000 lx, or at leastabout 80000 lx.

In at least one embodiment, the electromagnetic radiation is selectedfrom the group consisting of: ambient light, sunlight, incandescentlight, fluorescent light, LED light, laser light, and combinationsthereof. In at least one embodiment, the electromagnetic radiation isselected from the group consisting of: visible light, near or farultraviolet light, or near or far infrared light, and combinationsthereof. In at least one embodiment, the electromagnetic radiation islight. In at least one embodiment, the suitable light may be providedfrom any source capable of illuminating the substrate surface. In atleast one embodiment, the light is selected from the group consistingof: ambient sunlight, incandescent light, and fluorescent light. In atleast one embodiment, the light is provided by conventional sources suchas lamps and portable or battery-powered lights. Specific devices may bedeveloped or adapted for use with the crosslinking compositions andmethod described herein. In at least one embodiment, the appliance is ahair brush configured to incorporate LEDs In at least one embodiment,the light is laser light. Laser may be used to provide precisetargeting, for example. In at least one embodiment, the appliance ishybrid heat- and light-providing hair straightening irons.

In at least one embodiment, step (a) is carried out and thensubsequently step (b). In at least one embodiment, step (b) comprises(i) applying the crosslinking composition to keratin fibres; and thensubsequently (ii) exposing the composition to electromagnetic radiationhaving a wavelength of from about 300 nm to about 750 nm; andsubsequently (iii) mechanically shaping the keratin fibres with anappliance at a temperature of from about 80° C. to about 180° C. In atleast one embodiment, step (b) comprises (i) applying the crosslinkingcomposition to keratin fibres; and then subsequently (ii) mechanicallyshaping the keratin fibres with an appliance at a temperature of fromabout 80° C. to about 150° C.; and subsequently (iii) exposing thecomposition to electromagnetic radiation having a wavelength of fromabout 300 nm to about 750 nm. In at least one embodiment, step (b)comprises (i) applying the crosslinking composition to keratin fibres;and then subsequently (ii) mechanically shaping the keratin fibres withan appliance, wherein the temperature of the appliance is from about 50°C. to about 250° C., or from about 80° C. to about 180° C., and thenexposing the composition to electromagnetic radiation having awavelength of from about 300 nm to about 750 nm.

In at least one embodiment, (b) comprises elevating the temperature ofthe appliance to a temperature of from about 80° C. to about 180° C. Inat least one embodiment, (b) involves elevating the temperature of theappliance to a temperature of from about 50° C. to about 250° C. In atleast one embodiment, (b) involves elevating the temperature of theappliance to a temperature of from about 50° C., or from about 60° C.,or from about 70° C., or from about 80° C. to about 220° C., or to about200° C., or to about 180° C., or to about 170° C., or to about 160° C.,or to about 150° C., or to about 140° C., or to about 130° C.

In at least one alternative embodiment, the crosslinking composition isformed on the keratin fibres rather than provided prior to applying tokeratin fibres. For example, a crosslinking formulation comprising theactive agent and a cosmetically acceptable carrier is applied to thekeratin fibres and then subsequently, a photocatalyst formulationcomprising the photocatalyst is applied to the keratin fibres.

1^(st) Aspect

In at least one embodiment, the first aspect relates to a method forshaping keratin fibres comprising:

-   -   (a) providing a crosslinking composition, wherein the        crosslinking composition comprises:        -   an active agent, wherein the active agent is            2-hydroxypropane-1,2,3-tricarboxylic acid;        -   a photocatalyst being a hydroxy-substituted aromatic            compound;        -   a cosmetically acceptable carrier;        -   wherein the crosslinking composition has not been exposed to            electromagnetic radiation having a wavelength of 750 nm or            less for 30 min or more;    -   (b) applying the crosslinking composition to keratin fibres,        mechanically shaping the keratin fibres with an appliance at a        temperature of from about 80° C. to about 180° C. and exposing        the composition to electromagnetic radiation having a wavelength        of from about 300 nm to about 750 nm.        In at least one embodiment, the crosslinking composition further        comprises a viscosity-modifying agent and a conditioning agent.        In at least one embodiment, the crosslinking composition has a        pH of from about pH 3 to about pH 4.

2^(nd) Aspect

The method of the second aspect comprises: (a) providing a solidcomposition, wherein the solid composition comprises: an active agent,wherein the active agent is selected from the group consisting of:2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylicacid, a derivative thereof, and mixtures thereof; and wherein the activeagent has a molecular weight of about 500 g/mol or less; a photocatalystbeing a hydroxy-substituted aromatic compound; and then mixing the solidcomposition with a cosmetically acceptable carrier to form acrosslinking composition. The crosslinking composition is describedherein. In at least one embodiment, the active agent is2,2-dihydroxyethanoic acid. In at least one embodiment, the active agentis selected from the group consisting of:2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylicacid, and mixtures thereof. The second aspect has the advantage that itis not a requirement that solid composition has not been exposed toelectromagnetic radiation having a wavelength of 750 nm or less for 30min or more. This is because in solid form, the photocatalyst, ifexposed to electromagnetic radiation having a wavelength of 750 nm orless, cannot react with undesired materials e.g. container packaging.The solid composition is solid at 25° C.

3^(rd) Aspect—Crosslinking Composition

The third aspect relates to a crosslinking composition comprising theactive agent and a photocatalyst being a hydroxy-substituted aromaticcompound, wherein the hydroxy-substituted aromatic compound ismulticyclic. A crosslinking composition has been described extensivelyherein and these features are fully compatible and combinable with the3^(rd) aspect. In at least one embodiment, the active agent is2-hydroxypropane-1,2,3-tricarboxylic acid. In at least one embodiment,the crosslinking composition is a solid composition. A solid compositionhas been described herein and these features are fully compatible andcombinable with the 3^(rd) aspect. In at least one embodiment, thecrosslinking composition comprises a cosmetically acceptable carrier.

4^(th) Aspect—Use

The fourth aspect relates to the use of a crosslinking composition forshaping keratin fibres. A crosslinking composition has been describedextensively herein and these features are fully compatible andcombinable with the 4^(th) aspect. In at least one embodiment, the useis for straightening keratin fibres. In at least one embodiment, the useis for mechanically shaping keratin fibres. In at least one embodiment,the mechanical shaping of keratin fibres is selected from the groupconsisting of: straightening keratin fibres, such as human scalp hair orhuman eyelashes, and curling keratin fibres, such as human scalp hair orhuman eyelashes.

5^(th) Aspect—Kit

The fifth aspect relates to a kit. The kit comprises a crosslinkingformulation comprising the active agent. The active agent has beendescribed extensively herein and these features are fully compatible andcombinable with the 5^(th) aspect. In at least one embodiment, theactive agent is 2,2-dihydroxyethanoic acid. In at least one embodiment,the crosslinking formulation comprises a cosmetically acceptablecarrier. In at least one embodiment, the crosslinking formulation is inliquid form. In at least one embodiment, the crosslinking formulationcomprises from about 0.1% to about 99%, or from about 1% to about 98%,or from about 10% to about 97%, or from about 30% to about 95% water. Inat least one embodiment, the crosslinking formulation comprises aconditioning agent. Conditioning agents has been described extensivelyherein and these features are fully compatible and combinable with the5^(th) aspect. In at least one embodiment, the crosslinking formulationhas a pH of from about pH 3 to about pH 4. In at least one embodiment,the conditioning agent is selected from the group consisting of:epoxyaminosilane copolymers, and polysiloxane/polyurea block copolymers,and mixtures thereof. In at least one embodiment, the crosslinkingformulation comprises from about 0.01% to about 10% by weight, or fromabout 0.1% to about 8%, or from about 0.1% to about 5% hairstylingpolymer. In at least one embodiment, the crosslinking formulation is asolid.

The kit comprises a photocatalyst formulation comprising aphotocatalyst, wherein the photocatalyst is a hydroxy-substitutedaromatic compound. Photocatalysts agent have been described extensivelyherein and these features are fully compatible and combinable with the5^(th) aspect. In at least one embodiment, the hydroxy-substitutedaromatic compound is multicyclic. In at least one embodiment, thehydroxy-substituted aromatic compound is selected from the groupconsisting of: 8-quinolinol-1-oxide, 8-hydroxyquinoline, and mixturesthereof. In at least one embodiment, the photocatalyst formulation is insolid form.

In at least one embodiment, the kit comprises an appliance formechanically shaping keratin fibres. In at least one embodiment, theappliance is a hair brush configured to incorporate LEDs, which isoptionally heated. In at least one embodiment, the appliance is hybridheat- and light-providing hair straightening irons.

6^(th) Aspect—Process

The sixth aspect relates to a process for forming a crosslinkingcomposition. A crosslinking composition has been described extensivelyherein and these features are fully compatible and combinable with the6^(th) aspect. In at least one embodiment, the mixing together is viaagitation, for example by stirring. In at least one embodiment, thephotocatalyst is in solid form.

Alternative Aspect

An alternative aspect relates to the above described aspects but wherethe photocatalyst is selected from the group consisting of: sulfonatedpyrene compounds, onium salts, diazomethane derivatives, bissulfonederivatives, disulfuno derivatives, nitrobenzyl sulfonate derivates,sulfonic acid ester derivatives, sulfonic acid esters of anN-hydroxyimide, glyoxime derivatives, and mixtures thereof. In certainother embodiments, the photocatalyst is 8-hydroxy-1,3,6-pyrentrisulfonicacid trisodium salt (D&C Green 8). In at least one embodiment of thealternative aspect, the photocatalyst is a photobase. Photobasecatalysts may include derivatives of trityl alcohols such as, forexample, Malachite green. Photobase catalysts may also include acridinederivatives such as, for example,9-hydroxy-10-methyl-9-phenyl-9,10-dihydroacridine. Photobase catalystsmay also include photoactive carbamate-containing compounds.

Examples

The following examples further describe and demonstrate embodimentswithin the scope of the present invention. The examples are given solelyfor the purpose of illustration, and are not to be construed aslimitations of the present invention since many variations thereof arepossible without departing from its scope.

Example Crosslinking Compositions

A B C D E (*) 2-hydroxypropane- — 10 7.5 10 40 (10) 1,2,3-tricarboxylicacid 1,2,3,4- 5 — 7.5 10 40 (10) butanetetracarboxylic acid8-hydroxyquinoline 0.01 — — 0.01 — 7-cyano-2-naphthol — 0.005 — — 0.04(0.01) 8-quinolinol-1-oxide — — 0.01 0.01 0.04 (0.01) Preservatives¹ 1 11 1 3.98 (1)   Fragrance 2 2 2 2 7.97 (2)   Viscosity-modifying 2 2 2 27.97 (2)   agent² Conditioning agent³ 1 1 1 1 — Deionised water QSP QSPQSP QSP   — (QSP) buffered at pH 10⁴ KEY: ¹= sodium benzoate; ²= Acusol823 from Rohm and Haas; hydrophobically modified alkali soluble acrylicpolymer emulsion (HASE); ³= epoxyaminosilane copolymer as described inEP2214633B1 (filing date 30^(th) Oct. 2008) available from Momentive ™Performance Materials Inc., Columbus, Ohio, USA; ⁴= pH 10 buffer is astandard pH calibration buffer available from suppliers such as VWR,alternatively one can use water and modify the pH. Crosslinkingcomposition E is in solid form; (*) = wt % after mixing in deionisedwater.The crosslinking compositions A-D are typically at about pH 3-4.

Data

The hair straightening efficacy is tested for the crosslinkingcompositions of the present invention. Switches of low lift naturallycurly hair are employed. These are shampooed with a Pantene clarifyingshampoo to ensure the hair is in a clean state with no residues thatcould affect the end result. The switches are then rinsed. Excess wateris removed from the hair by wringing out the switches. The switches aretreated with a crosslinking composition which is pre-prepared in a darkroom. The crosslinking composition comprises: 5% active agent; 100 ppm8-hydroxyquinoline; 100 ppm 8-quinolinol-1-oxide; QSP water buffered atpH 10. These ingredients are mixed on a spinner plate for 30 mins. Thecrosslinking composition is stored in an amber bottle or a bottlecovered in electrical tape to ensure no light access to the crosslinkingcomposition. 0.25 g of crosslinking composition per 1 g hair isemployed. The crosslinking composition is left on the hair for 30minutes. As a control experiment, hair switches are treated exactly thesame but no crosslinking composition is applied to the switch—thecontrol switches are allowed to rest damp for 30 minutes. After thistime, the hair is blow dried and brushed. The switches are thenmechanically straightened with hybrid light and heat emittingstraightening irons (at 250° F. [121° C.] and emitting UV light at 380nm) with 8 passes. The switches are then imaged. To simulate durability,the switches are then given one wash-and-dry cycle. One wash-and-drycycle involves shampooing with a Hairtrition shampoo (Hairtrition ColorProtect sulfate-free shampoo from Zotos), rinsing and then drying in ahot box. Once dry the switches are imaged again. The switches are thengiven 4 further wash-and-dry cycles. Once dry the switches are imagedagain. An expert grader gives the images of the switches a score on a0-10 scale. The scale is a standard scale set as curly hair having 4-5nodes of curls is a score of 0 and very straight hair is a 10. Thus, theswitches are compared to a normal state of hair. Using an expert graderis reliable because the grader is trained on measuring/scaling theconfiguration of the hair from straight to curly in a consistent way. Asper the FIG. 1, the bars with the diagonal shading lines show the scoreby the expert grader after one wash-and-dry cycle and the bars with thehorizontal shading lines show the score by the expert grader after fivewash-and-dry cycles. Conclusions from these data: actives in thecrosslinking composition show excellent hair straightening benefitversus a control experiment where no crosslinking composition is used.The hair straightening benefit is durable in that the benefit is seenfollowing one wash-and-dry cycle.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or patent publication, is hereby incorporated herein by referencein its entirety unless expressly excluded or otherwise limited. Thecitation of any document is not an admission that it is prior art withrespect to any document disclosed or claimed herein or that it alone, orin any combination with any other reference or references, teaches,suggests or discloses any such embodiment. Further, to the extent thatany meaning or definition of a term in this document conflicts with anymeaning or definition of the same term in a document incorporated byreference, the meaning or definition assigned to that term in thisdocument shall govern.

While particular embodiments have been illustrated and described herein,it should be understood that various other changes and modifications maybe made without departing from the spirit and scope of the claimedsubject matter. Moreover, although various aspects of the claimedsubject matter have been described herein, such aspects need not beutilized in combination. It is therefore intended that the appendedclaims cover all such changes and modifications that are within thescope of the claimed subject matter.

What is claimed is:
 1. A method for shaping keratin fibres comprising:(a) providing a crosslinking composition, wherein the crosslinkingcomposition comprises: an active agent, wherein the active agent isselected from the group consisting of:2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylicacid, a derivative thereof, and mixtures thereof; and wherein the activeagent has a molecular weight of about 500 g/mol or less; a photocatalystbeing a hydroxy-substituted aromatic compound; a cosmetically acceptablecarrier; wherein the crosslinking composition has not been exposed toelectromagnetic radiation having a wavelength of about 750 nm or lessfor about 30 min or more; (b) applying the crosslinking composition tokeratin fibres, mechanically shaping the keratin fibres with anappliance at a temperature of from about 80° C. to about 180° C. andexposing the composition to electromagnetic radiation having awavelength of from about 300 nm to about 750 nm.
 2. A method for shapingkeratin fibres comprising: (a) providing a solid composition, whereinthe solid composition comprises: an active agent, wherein the activeagent is selected from the group consisting of:2-hydroxypropane-1,2,3-tricarboxylic acid, 1,2,3,4-butanetetracarboxylicacid, a derivative thereof, and mixtures thereof; and wherein the activeagent has a molecular weight of about 500 g/mol or less; a photocatalystbeing a hydroxy-substituted aromatic compound; and then mixing the solidcomposition with a cosmetically acceptable carrier to form acrosslinking composition; (b) applying the composition to keratinfibres, mechanically shaping the keratin fibres with an appliance at atemperature of from about 80° C. to about 180° C. and exposing thecomposition to electromagnetic radiation having a wavelength of fromabout 300 nm to about 750 nm.
 3. The method of claim 1, wherein thehydroxy-substituted aromatic compound is selected from the groupconsisting of: 8-hydroxyquinoline, 8-hydroxyquinoline sulfate,8-quinolinol-1-oxide, 5-hydroxyquinoline, 6-hydroxyquinoline,7-hydroxyquinoline, 5-iodo-7-sulfo-8-hydroxyquinoline,5-fluoro-8-hydroxyquinoline, 5-fluoro-7-chloro-8-hydroxyquinoline,5-fluoro-7-bromo-8-hydroxyquinoline, 5-fluoro-7-iodo-8-hydroxyquinoline,7-fluoro-8-hydroxyquinoline, 5-chloro-8-hydroxyquinoline,5,7-dichloro-8-hydroxyquinoline, 5-chloro-7-brono-8-hydroxyquinoline,5-chloro-7-iodo-8-hydroxyquinoline, 7-chloro-8-hydroxyquinoline,5-bromo-8-hydroxyquinoline, 5-bromo-7-chloro-8-hydroxyquinoline,5,7-dibromo-8-hydroxyquinoline, 5-bromo-7-iodo-8-hydroxyquinoline,7-bromo-8-hydroxyquinoline, 5-iodo-8-hydroxyquinoline,5-iodo-7-chloro-8-hydroxyquinoline, 5,7-diiodo-8-hydroxyquinoline,7-iodo-8-hydroxyquinoline, 5-sulfonic acid-8-hydroxyquinoline,7-sulfonic acid-8-hydroxyquinoline, 5-sulfonicacid-7-iodo-8-hydroxyquinoline, 5-thiocyano-8-hydroxyquinoline,5-chloro-8-hydroxyquinoline, 5-bromo-8-hydroxyquinoline,5,7-dibromo-8-hydroxyquinoline, 5-iodo-8-hydroxyquinoline,5,7-diiodo-8-hydroxyquinoline, 7-azaindole, 7-cyano-2-naphthol,8-cyano-2-naphthol, 5-cyano-2-naphthol,1-hydroxy-3,6,8-pyrenetrisulfonic acid, trans-3-hydroxystilbene,2-hydroxymethylphenol, Pelargonidin, and mixtures thereof.
 4. The methodof claim 1, wherein the mechanical shaping of keratin fibres is selectedfrom the group consisting of: straightening keratin fibres, such ashuman scalp hair or human eyelashes, and curling keratin fibres, such ashuman scalp hair or human eyelashes.
 5. The method of claim 1, whereinthe appliance comprises light-emitting diodes.
 6. The method of claim 1,wherein the wherein the photocatalyst can be activated to aphoto-excited state by excitation with incident radiation with awavelength from about 300 nm to about 750 nm and wherein the applicanceemits radiation with a wavelength from about 300 nm to about 750 nm. 7.The method of claim 1, wherein the hydroxy-substituted aromatic compoundis 8-hydroxyquinoline.
 8. The method of claim 1, wherein the compositionis substantially free of: formaldehyde, derivatives of formaldehyde,formalin, and any compound that produces formaldehyde upon heating. 9.The method of claim 1, wherein the method does not comprise a rinsingstep between step (a) and step (b).
 10. The method of claim 1, whereinthe active agent is 2-hydroxypropane-1,2,3-tricarboxylic acid.
 11. Themethod of claim 1, wherein the crosslinking composition comprises atotal amount of active agent and wherein the total amount of activeagent is from about 0.1% to about 40% active agent.
 12. The method ofclaim 1, wherein the crosslinking composition further comprises a secondactive agent.
 13. The method of claim 1, wherein the crosslinkingcomposition comprises from about 10% to about 97% water.
 14. The methodof claim 1, wherein the crosslinking composition comprises from about 10ppm to about 500 ppm photocatalyst being a hydroxy-substituted aromaticcompound.
 15. A crosslinking composition for shaping keratin fibrescomprising: an active agent, wherein the active agent is selected fromthe group consisting of: 2-hydroxypropane-1,2,3-tricarboxylic acid,1,2,3,4-butanetetracarboxylic acid, and mixtures thereof; aphotocatalyst being an hydroxy-substituted aromatic compound, whereinthe hydroxy-substituted aromatic compound is multicyclic; a cosmeticallyacceptable carrier.
 16. The crosslinking composition of claim 15,wherein the active agent is 2-hydroxypropane-1,2,3-tricarboxylic acid.17. The crosslinking composition of claim 15, wherein thehydroxy-substituted aromatic compound is 8-hydroxyquinoline.